Pear heartworm, belonging to the Lepidoptera borer family referred to as pear large, also known as hanging ghost, is the main insect pest on pear trees, which has a great impact on the yield and quality of pears.
Pear large heartworm occurs one to two generations a year, mainly harmful to flower buds and young fruits, with small larvae in the bud to do white cocoon overwintering, early spring in late March, larvae in the wintering bud activity, early April, when the flower buds expand, the larvae began to transfer harm to the flower buds, the average temperature of the day reached 13 to 15 degrees, about ten days, most of the transfer to the flower buds, when the harm drilled in from the base of the buds, and with silk and fragments to seal the entrance, the larvae eat the flower shaft, around the flower tone wilted and drooped, in mid-May, when the mother finger of the young fruit is large, the larvae begin to harm the fruit, Larvae infest fruit directly to the heart of the fruit, from the worm hole to discharge a large amount of feces, the end of the month to early July, for the peak of the fruit, the larvae can harm 2 to 3 flower buds in their lifetime, and 1 to 4 young fruits, the larvae mature in the fruit pupae, the larvae crawl out of the fruit before pupal, the fruit stalk is fixed with filaments, hung on the tree, the pupa peak in early and mid-July, adult insects begin to appear in the flower buds after feathering, in early August, the first generation of larvae appear, endangering the flower buds formed that year, and the cocoon begins to overwinter in mid-to-late August.
Prevention and control methods
1. Combine pruning, shear the insect buds.
2, when the buds of pear trees germinate in spring, from the end of March to the beginning of April, the early stage of overwintering larval germination, zinc thiophos and high-efficiency cypermethrin are sprayed for control.
From March, July to August, the first generation of larvae appeared in large numbers and sprayed Bordeaux liquid and octathion emulsion plus high hydropermethrin for two consecutive times, and the diseases and insects were treated.
From April, June to July, the worm fruit is removed.
